The disclosure relates generally to hand brake mechanisms adapted for use on railway cars and more particularly, to mechanisms of the quick-release type having a prolonged release.
U.S. Pat. Nos. 3,425,294; 3,988,944 and 4,291,793 disclose hand brake mechanisms or actuator of the quick-release type, which are adapted for use on railway cars. The disclosed mechanisms also incorporate structure providing for gradual release of the car brakes. Both gradual and quick releases are effected without spinning of the hand wheel which is manually rotated for application and for gradual release of the brakes. More particularly, two clutches are arranged in series relationship in a power train or transmission from the hand wheel to the car brakes. A self-energizing friction clutch associated with coaxial separate shafts in the power train provides for gradual release of the brakes. A manually-operated clutch of the jaw type provides for quick release of the brakes.
The mechanism of the patents includes a pivoted yoke assembly having shift lever or fork components, and a cam shaft having a handle or lever connected thereto for manual operation. The cam shaft is provided with a cam operating in one direction of rotation of the shaft to pivotally move the yoke assembly so as to separate components of the quick-release clutch for releasing the brakes. A second cam on the cam shaft functions upon rotation of the cam shaft in the opposite direction to cam the yoke assembly in a direction to drivingly engage the clutch components, and to assist a biasing spring in maintaining the engagement of the components.